Digital map of possible bat habitats for the Pacific Northwest, a contribution to the Interior Columbia River Basin Ecosystem Management Project

1996 ◽  
Author(s):  
Thomas P. Frost ◽  
Gary L. Raines ◽  
Carl L. Almquist ◽  
Bruce R. Johnson
Keyword(s):  
Pacific Northwest ◽  
River Basin ◽  
Ecosystem Management ◽  
Columbia River ◽  
Columbia River Basin ◽  
Digital Map ◽  
The Pacific ◽  
Management Project

Response of the Columbia River Fluvial System to Holocene Climatic Change

1992 ◽  
Vol 37 (1) ◽  
pp. 42-59 ◽  
Author(s):  
James C. Chatters ◽  
Karin A. Hoover
Keyword(s):  
Pacific Northwest ◽  
River Basin ◽  
Columbia River ◽  
River System ◽  
Climatic Conditions ◽  
Columbia River Basin ◽  
Fluvial System ◽  
Temperature And Precipitation ◽  
The Pacific ◽  
Floodplain Development

AbstractAn understanding of the response of a fluvial system to past climatic changes is useful for predicting its response to future shifts in temperature and precipitation. To determine the response of the Columbia River system to previous climatic conditions and transitions, a well-dated sequence of floodplain development in the Wells Reservoir region was compared with the paleoenvironmental history of the Columbia River Basin. Results of this comparison indicate that aggradation episodes, occurring approximately 9000-8000, 7000-6500, 4400-3900, and 2400-1800 yr B.P., coincided with climatic transitions that share certain characteristics. The inferred climates associated with aggradation had at least moderate rates of precipitation that occurred mainly in winter coupled with moderate winter temperatures. Such conditions would have resulted in the buildup of snowpacks and a high frequency of rain-on-snow events. The warming and precipitation increases predicted for the Pacific Northwest under most CO2-doubling scenarios are likely to repeat these conditions, which could increase the frequency of severe, sediment-laden floods in the Columbia River Basin.

Presettlement overharvest of upper Columbia River beaver populations

1974 ◽  
Vol 52 (12) ◽  
pp. 1519-1521 ◽  
Author(s):  
Donald R. Johnson ◽  
David H. Chance
Keyword(s):  
Pacific Northwest ◽  
River Basin ◽  
Age Structure ◽  
Castor Canadensis ◽  
Age Groups ◽  
Columbia River ◽  
Columbia River Basin ◽  
Steady Decrease ◽  
The Pacific ◽  
Social Upheaval

Beaver (Castor canadensis) populations of the Pacific Northwest interior underwent a drastic decline from 1835 to 1850, as evidenced by a steady decrease in harvest. There is little evidence that price changes, company trapping policy, losses to rival traders, or social upheaval had a significant effect on the returns from the upper Columbia River basin. The proportion of juveniles increased in harvests from exploited populations because of (1) changes in age structure, (2) reduced trappability of the older age groups, or (3) both of these factors. Certain populations showed evidence of recovery beginning about 1850.

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